Bonding between precipitated silica and epoxidized natural rubber in the presence of silane coupling agent

Results of Monsanto rheometic studies and measurements of physical properti es reveal that precipitated silica interacts chemically with epoxidized nat ural rubber (ENR) during high temperature (180 degrees C) molding and the e xtent of chemical interaction increases in the presence of silane coupling agent, namely N-3(N-vinyl benzyl amino) ethyl-gamma-amino propyl trimethoxy silane monohydrogen chloride. Fourier transform infrared spectroscopic stu dies show that silica is bonded to ENR through formation of Si-O-C bond, wh ereas in the presence of silane coupling agent, silica is bonded to the cou pling agent through Si-O-Si bond, and ENR is bonded to the coupling agent t hrough C-N-C bond formation. (C) 1999 John Wiley & Sons, Inc.